First look at simple, code based discount promotions.
Add Islay Shop's application controller stuff for initialising orders to a controller extensions module, so individual shops don't need to include it.
Move the order dump/load stuff out to the modules where it belongs
Display the discounts in Islay
Stop auto-injecting the shop's controller methods into Islay's Public ApplicationController
Fix the point where totals are calculated when items are updated
Show discounts wherever the basket is displayed
Remove fat-finger-print.